2014-2015 MAZDA3 – NOISE FROM FUEL TANK (UNDER REAR SEAT) WHEN IDLING AND FUEL TANK IS FULL
APPLICABLE MODEL(S)/VINS
2014-15 Mazda3 vehicles (Japan built – US and Canada spec only) with VINs lower than JM1BM******235980 (produced before October 1, 2014)
2014-15 Mazda3 vehicles (Mexico built- US and Canada spec only) with VINs lower than 3MZBM******195832 (produced before February 17, 2015)
Tapping noise coming from inside the fuel tank (under the rear seat) when idling after the fuel tank has been filled up.
The noise disappears after driving and consuming some fuel.
The concern will likely occur if the fuel tank is overfilled (more fuel is added after the fuel pump nozzle shuts off automatically) or filled up normally in high ambient temperatures and the fuel expands.
- For Japan built models: This noise is caused when the float inside the roll over valve (ROV) moves up and down when the tank is overfilled. To correct the problem, the ROV has been modified to restrict the up and down movement of the float.
- For Mexico built models: The noise is caused by air bubbles from the shut off valve (SOV) when the fuel tank is overfilled. To correct the problem, the SOV has been improved to prevent this concern.
REPAIR PROCEDURE
- Confirm with the customer if fuel is added to the tank after the fuel pump nozzle shuts off automatically when filling up. If YES, advise the customer to stop. This is dangerous as fuel overflow or leakage can occur as warned in the Owner’s Manual and the concern in this TSB is likely to occur.
WARNING IN OWNER’S MANUAL
DO NOT continue refueling after the fuel pump nozzle shuts off automatically: Continuing to add fuel after the fuel pump nozzle has shut off automatically is dangerous because overfilling the fuel tank may cause fuel overflow or leakage. Fuel overflow and leakage could damage the vehicle and if the fuel ignites it could cause a fire and explosion resulting in serious injury or death.
- Replace the fuel tank with a modified one. Refer to the instructions on MS3 online or the Workshop Manual (section 09-10).
PART(S) INFORMATION
For Japan built Mazda3:
| Part Number | Description | Qty. | Notes |
| BHN1-42-110D | Fuel Tank Assembly | 1 | — |
| BBM2-42-166A | Gasket for fuel pump | 1 | Replacement part |
PE23-40-305
Genuine Mazda Parts - Gasket (PE23-40-305) Assorted One Size
Last update on 2026-06-17 / Affiliate links / Images from Amazon Product Advertising API | Gasket for TWC | 2 | |
| 9994-61-000 No products found. | Nut for TWC | 4 | |
| KD53-42-762 | Pad, Fuel Tank | 5 | Replacement parts (Pads will be attached on new fuel tank.) |
For Mexico built Mazda3:
| Part Number | Description | Qty. | Notes |
| BJT6-42-110D | Fuel Tank Assembly | 1 | — |
| BJT6-42-165 | Gasket for fuel pump | 1 | Replacement part |
| PE23-40-305
Genuine Mazda Parts - Gasket (PE23-40-305) Assorted One Size
Last update on 2026-06-17 / Affiliate links / Images from Amazon Product Advertising API | Gasket for TWC | 2 | |
| 9994-61-000 No products found. | Nut for TWC | 4 | |
| BJS7-42-761 | Pad, Fuel Tank | 3 | Replacement parts (Pads will be attached on new fuel tank.) |
| BJT6-42-761 | 2 | ||
| BJS7-42-765 | 3 | ||
| BJT6-42-765 | 3 |
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